Why does the { position affects this Javascript code?

Question

I spent a fair bit of time on this Javascript issue (you can tell I am a JS noob):

Take some well written Javascript code like this example of the Revealing Module P

Answer 1

Because the ECMA standard section 12.9 states you can't have a new line between the return keyword and its expression.

    ReturnStatement :
       return ;
       return [no LineTerminator here] Expression ;